The corticostriatal system, which includes the striatum, ventromedial prefrontal cortex (vmPFC), orbitofrontal cortex (OFC), thalamus, insula, hippocampus, and anterior cingulate cortex (ACC), among other structures, is critical for reward processing (for review see [91•]). Emerging neurogenetics research [92•] suggests that genetic variation associated with addiction risk also predicts individual differences in corticostriatal function, structure, and connectivity, providing putative mediating neural mechanisms through which these polymorphisms promote addictions. While the vast majority of addiction-related neurogenetics research has focused on genetic variation in the dopaminergic system [93, 94], we focus our review on research evaluating variation within GABRA2, CHRNA5-CHRNA3-CHRNB4, and CNR1.
